Fluids

Fluids

Topics relate to Fluent, CFX, Turbogrid and more

I’m getting the following CFX error reported in the out file. What does it mean?

TAGGED: ,

    • mcoderon
      Ansys Employee

       +----------------------------------------------------------------------------------------+

       |        *** INSUFFICIENT MEMORY ALLOCATED ***             |

       |                                                             |

       | ACTION REQUIRED : Increase the character stack memory size.    |

       |                                                             |

       | Details :                                                      |

       | Requested space    :    2608880 words                      |

       | Current allocated space :    731286 words                    |

       | Current used space   :     5720 words                       |

       | Current free space   :    725566 words                      |

       | Number of free areas  :       1                              |

       +----------------------------------------------------------------------------------------+

    • rfblumen
      Ansys Employee
      When the CFX solver is launched, the amount of RAM needed for the problem has to be allocated at the beginning of the run.It estimates the required memory based on the model size, physics, number of interfaces, etc.The CFX solver cannot dynamically allocate more memory after the run starts if it finds it needs more.In certain cases, the solver underestimates the memory required and you will get an error similar to the above.

      The important thing to note is that there are three places where the CFX solver can run out of memory:

      -Interpolator
      -Partitioner
      -Solver

      Each of these is independent of the other and each has their own memory allocation under their respective tabs in the "Define Run" window.For instance, if the Interpolater runs out of memory and you instead allocate more memory to the Solver, then it won't address the memory issue with the Interpolater and the error will re-occur. It's important when a memory allocation occurs to scroll up in the out file and note in what section (Interpolater, Partitioner, Solver) the error occurred and allocate more memory for that specific section.
Viewing 1 reply thread
  • You must be logged in to reply to this topic.